It is well-known that in an integrated printhead-ink cartridge, the printhead and the ink cartridge are non-removably connected together therein the cover of the ink cartridge is fixed to the printhead frame by non-removable methods such as welding or the like. Generally, the ink is stored directly inside a printhead chamber and when the ink is depleted, the entire ink cartridge together with the printhead is required to be replaced and discarded. This results in high costs both in manufacturing and in using the printing consumables. As a result, it causes not only unnecessary waste but also environment pollution because of the large amount of this mixed electronic waste which is difficult to dispose of and recycle.
In dealing with the problems mentioned above, there exists a segregated printhead-ink cartridge that is made from modifying an integrated printhead-ink cartridge, in which the ink cartridge is detachably connected with the printhead and is an independent functional entity inside the printhead. The ink cartridge itself is a single-use disposable consumable whereas the printhead can be used repeatedly. The securement of the ink cartridge to the printhead basically employs one of the following methods: (1) a securement method using raised ribs integrally connected with the ink cartridge, wherein the raised ribs match with the grooves which are formed from complicated mechanical machining process on the inside wall surfaces of the printhead frame; (2) a securement method using the locking tabs of elastic cartridge-claws which are integrally connected with the ink cartridge, wherein the locking tabs match with the outer frame edge of the printhead; and (3) a securement method using a movable sleeve which is separate from the ink cartridge, wherein the movable sleeve is open at one end and slidably fits over the outer frame edge of the printhead. In method (1) above, the fact that the grooves have to be formed by a complicated machining process and the frame wall of the printhead is not elastic enough to allow the raised ribs to fit and lock into the grooves or to be easily pulled out of the grooves makes the removal and installation of the ink cartridge very difficult. Thus, ordinary users are not able to process and recycle the depleted ink cartridge but instead have to buy the entire set of printhead and ink cartridge provided by some specialised manufacturers. In method (2) above, the fact that the elastic cartridge-claws are integrally connected to the ink cartridge means that it is an unnecessary waste of materials after the single-use ink cartridge is depleted of ink. In method (3) above, the fact that the slidable sleeve is not fully constrained and is therefore prone to move along the outer frame edge of the printhead under certain abnormal circumstances means that the securement of the ink cartridge is not quite reliable.